CONTENTS. 



A History of the " small black erratic Ant." By Dr. G. Lincecum, 



of Texas 101 



Notes on some members of the Feldspar Family. By Isaac Lea.. 110 



Observations on Chaetetes and some related Genera, in regard to 

 their Systematic Position ; with an appended description of 

 some New Species. By Dr. Carl Rominger 113 



Fourth Contribution to the Herpetology of Tropical America. 



By Prof. E. D. Cope 123 



Description of five New Species of the Genus Unio. By Isaac 



Lea 133 



Description of two New Species of the Genus Lithasia. By 



Isaac Lea 133 



A Critical Review of the Family Procellariidse : Part IV ; em- 

 bracing the iEstrelateae and the Prionese. By Dr Elliott 

 Coues,U. S. A 134 



Critical Review of the Family Procellariidae; Part V; embracing 

 the Diomedeinae and the Halodrominae. With a general 

 Supplement. By Elliott Coues, M.D., U.S. A 172 



Observations on the Cranial Forms of the American Aborigines, 

 based upon specimens contained in the Collection of the 

 Academy of Natural Sciences of Philadelphia. By J. Ait- 

 ken Meigs, M.D 197 



